The need for more efficient and sustainable refrigeration systems has promoted the development of new configurations. Subcooling have shown to improve the coefficient of performance whereas thermal energy driven configurations allow renewable sources to be employed. In this study thermodynamic models have been developed for simple, suction line heat exchanger, integrated and dedicated subcooling vapor compression systems using R-134a as the primary refrigerant and for a single-stage absorption refrigeration system with H2O/LiBr. The variation exhibited by the performance of the refrigeration systems is examined at various operating conditions finding that COP increases as condenser temperature decreases and evaporator temperature increases; high COP values are obtained with increasing generator temperature and LiBr concentration in the case of the absorption system. Low and zero emissions associated to subcooling strategies and absorption systems, due to the higher efficiencies and renewable character of the energy source respectively, were obtained when comparing the environmental impact.